(373ac) Optimal Gas Treatment and Coal Blending for Reduced Emissions in Power Plants
In this work, a framework is developed to select among different denitrification and desulfurization technologies and their relative position along the flue gas treatment chain of a power plant for the future selection of technologies in a local power plant. It consists of a two-stage procedure. The first stage corresponds to the pre-screening of the technologies available based on industrial know-how. The second one consists of formulating a superstructure model  of alternative technologies from the boiler to the discharge of the flue gas involving denitrifier, desulfurizer and particle removal. Surrogate models for each of the units are developed based on experimental and industrial data providing a flexible framework to evaluate and design the flue gas treatment process. Once the plant is installed, it may have to process different coals. Price fluctuations in coal, supply agreements, social reasons and the ever-changing policies can result in the interest or need to process different types of coal. Coal blending is a well-known topic aiming at selecting the proper mixture of coal types to meet sulphur content and optimize the combustion properties . However, the blending studies in the literature are limited to the addition of process constraints on the composition of the feed to the mathematical formulation of the problem. In this work we have used this approach to formulate a coal blending problem that includes a detail model of the technologies responsible for flue gas processing as a decision making tool to help select the coal blend among three coal types, imported, national and crude tar coal that are typically used in a local power plant nearby.
The optimization suggests the use of electrostatic precipitation, followed by catalytic NOx removal and dry SO2 removal. Next, a coal blending problem has also been solved. When only treatment costs are considered, the use of imported coal is recommended, but an increase of 4% in its price can change the decision into the use of national coal. If the energy within the coal is added to the objective function, crude tar coal is included in the blend and imported coal is used to maintain the emissions within limits. LSFO is the selected technology for SO2 removal.
Staff of âLa Roblaâ power plant for their support and fruitful conversations.
 NLWA (2014) NORTH LONDON HEAT AND POWER PROJECT â FLUE GAS TREATMENT PLANT OPTIONS
 Grossmann, I. E, Caballero J. A, Yeomans H. Advances in mathematical programming for the synthesis of process systems. Latin American Applied Research, 2000. 30:263-284
 Shih JS, Frey HC.. Coal blending optimization under uncertainty. Eur. J. Oper. Res., 1995; 83, 3(22): 452-465